1. Field of the Invention
The present invention relates to host based printers, and, more particularly, to a method of printing with a host based printer using an internal font.
2. Description of the Related Art
A host based printer is designed to allow the host system to which it is attached to do much of the data processing functions that were historically performed in the printer itself. These functions included parsing of data, font image storage, font image manipulation, along with other tasks. By moving these functions into the system to which the printer is attached, the printer may be designed to be less expensive. The savings come from reduced Read Only Memory (ROM), Random Access Memory (RAM), and processing power requirements.
A host based printer may be designed such that the printer is not capable of printing anything without the necessary software running in the host system. A problem is that the printer cannot perform stand alone printing for demonstration, printer maintenance purposes, or host system maintenance in the case that the host software cannot be loaded or for whatever reason will not function properly. Accordingly, ASCII text files such as configuration and batch files cannot be printed if the host software is not functioning.
What is needed in the art is a method of printing text in a rudimentary fashion that allows a host based printer to print printer maintenance data and system configuration files without assistance from the host, and without requiring large amounts of ROM for the storage of font data, RAM for font manipulation, or processing power for handling the font data.
The present invention provides a method of printing diagnostics and internal test results in a rudimentary fashion with a host based printer, without an attached computer, and with a minimum of ROM, RAM and processing power within the host based printer. Safeguards are provided to terminate printing in the rudimentary printing mode if data which is not compatible with the rudimentary printing mode is received from the host by the printer.
The invention comprises, in one form thereof, a method of printing a print image on a print medium using a printer including the step of providing a text printing mode, wherein a first predetermined number of bits identify a selected character to be printed. A host based printing mode is provided wherein selected bits each indicate whether a corresponding pixel should be printed. The printer is initialized to enable each of the text printing mode and the host based printing mode. A second predetermined number of bits of a data stream associated with the print image to be printed are received within the printer. The second predetermined number of bits is examined to determine a presence of a command therein. Upon determining the presence of the command, the text printing mode is disabled. However, in the absence of the command, the text printing mode and the host based printing mode remain enabled. The printer is enabled to print in an enabled printing mode. The enabled printing mode includes one of the text printing mode or the host based printing mode. The printer is used to print on the print medium in the enabled printing mode.
An advantage of the present invention is that the host based printer can perform stand alone printing when the host software is not functioning.
Another advantage is that the host based printer can perform stand alone printing with a minimum of memory and processing power.
Yet another advantage is that printing in the stand alone mode is terminated if data which is not compatible with the rudimentary printing mode is received from the host by the printer.